25,427 research outputs found
Cooling of jarred cheese spreads
An overall heat balance and a model for the cooling of an individual jar are derived for glass jars of cheese spread on Kraft's production line. Good agreement is found between the model predictions and temperature data collected by Kraft. A possible cause of boiling in the cheese is proposed and steps for its prevention are suggested
Microwave radiometric studies and ground truth measurements of the NASA/USGS Southern California test site
The field measurement program conducted at the NASA/USGS Southern California Test Site is discussed. Ground truth data and multifrequency microwave brightness data were acquired by a mobile field laboratory operating in conjunction with airborne instruments. The ground based investigations were performed at a number of locales representing a variety of terrains including open desert, cultivated fields, barren fields, portions of the San Andreas Fault Zone, and the Salton Sea. The measurements acquired ground truth data and microwave brightness data at wavelengths of 0.8 cm, 2.2 cm, and 21 cm
Electromagnetic Moments of the Baryon Decuplet
We compute the leading contributions to the magnetic dipole and electric
quadrupole moments of the baryon decuplet in chiral perturbation theory. The
measured value for the magnetic moment of the is used to determine
the local counterterm for the magnetic moments. We compare the chiral
perturbation theory predictions for the magnetic moments of the decuplet with
those of the baryon octet and find reasonable agreement with the predictions of
the large-- limit of QCD. The leading contribution to the quadrupole
moment of the and other members of the decuplet comes from one--loop
graphs. The pionic contribution is shown to be proportional to (and so
will not contribute to the quadrupole moment of nuclei), while the
contribution from kaons has both isovector and isoscalar components. The chiral
logarithmic enhancement of both pion and kaon loops has a coefficient that
vanishes in the limit. The third allowed moment, the magnetic octupole,
is shown to be dominated by a local counterterm with corrections arising at two
loops. We briefly mention the strange counterparts of these moments.Comment: Uses harvmac.tex, 15 pages with 3 PostScript figures packed using
uufiles. UCSD/PTH 93-22, QUSTH-93-05, Duke-TH-93-5
Low-speed inducers for cryogenic upper-stage engines
Two-phase, low-speed hydrogen and oxygen inducers driven by electric motors and applicable to the tug engine were designed and constructed. The oxygen inducer was tested in liquid and two-phase oxygen. Its head and flow performance were approximately as designed, and it was able to accelerate to full speed in 3 seconds and produce its design flow and head. The analysis of the two-phase data indicated that the inducer was able to pump with vapor volume fractions in excess of 60 percent. The pump met all of its requirements (duration of runs and number of starts) to demonstrate its mechanical integrity
Multiplexed Memory-Insensitive Quantum Repeaters
Long-distance quantum communication via distant pairs of entangled quantum
bits (qubits) is the first step towards more secure message transmission and
distributed quantum computing. To date, the most promising proposals require
quantum repeaters to mitigate the exponential decrease in communication rate
due to optical fiber losses. However, these are exquisitely sensitive to the
lifetimes of their memory elements. We propose a multiplexing of quantum nodes
that should enable the construction of quantum networks that are largely
insensitive to the coherence times of the quantum memory elements.Comment: 5 pages, 4 figures. Accepted for publication in PR
New, nearby bright southern ultracool dwarfs
We report the discovery of twenty-one hitherto unknown bright southern
ultracool dwarfs with spectral types in the range M7 to L5.5, together with new
observations of a further three late M dwarfs previously confirmed. Three more
objects are already identified in the literature as high proper motion stars;we
derive their spectral types for the first time. All objects were selected from
the 2MASS All Sky and SuperCOSMOS point source databases on the basis of their
optical/near-infrared colours, -band magnitudes and proper motions. Low
resolution (R 1000) spectroscopy with the ESO/NTT SOFI spectrograph
has confirmed the ultracool nature of 24 targets, out of a total of 25
candidates observed. Spectral types are derived by direct comparison with
template objects and compared to results from HO and FeH indices. We also
report the discovery of one binary, as revealed by SOFI acquisition imaging;
spectra were taken for both components. The spectral types of the two
components are L2 and L4 and the distance 19 pc. Spectroscopic distances
and transverse velocities are derived for the sample. Two L5 objects lie
only 10 pc distant. Such nearby objects are excellent targets for
further study to derive their parallaxes and to search for fainter, later
companions with AO and/or methane imaging.Comment: 11 pages, 10 figures, accepted to MNRA
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